package 国庆编程作业;

import java.util.LinkedList;
import java.util.Queue;

public class QueueTest {

    public static void main(String[] args) {
        Queue<String> queue = new LinkedList<String>() ;
        queue. offer("string"); // add
        System. out. println(queue. poll() );//集合没有值返回null
        System. out. println(queue. remove() );//集合没有值会报错


        System. out. println(queue. size() );
    }
}
